<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		div {
			width: 300px;
			height: 2000px;
			padding: 10px;
			margin: 10px;
			background-color: #58a;
		}
		body {
			margin: 0;
			border: 10px solid black;
		}
		html {
			overflow: hidden;
		}
	</style>
</head>
<body>
	<div>div：height:2000px;padding:10px;border:10px;margin:10px;这里是为了撑开内容区域，让它出现滚动条，点击显示滚动条的scrollHeight</div>
	<script>

		// 滚动条相关尺寸：

		document.onclick = function () {
			var scrollT = document.documentElement.scrollHeight;
			document.write(scrollT);
		}

	</script>
</body>
</html>